Hi, I'm Rune and I live in norway, I have an designo varicolour mystic blue sl 55, and I think it's the best choice, also very few of them :-)
It's especially nice to see the changing look of the paint when its dark or lighter, as you'll see in the photos.
The mercedes dealer can probably get you the same paint.
Good luck with your new colour!!
Here's a link:
SL 55 AMG
Yours sincerely
Rune Solem